Remove wxUSE_UNICODE checks as they're always true now

Also remove all code guarded by "#if !wxUSE_UNICODE".

src/common/sstream.cpp

@@ -35,16 +35,10 @@
 // TODO:  Do we want to include the null char in the stream?  If so then
 // just add +1 to m_len in the ctor
 wxStringInputStream::wxStringInputStream(const wxString& s)
-#if wxUSE_UNICODE
     // FIXME-UTF8: use wxCharBufferWithLength if we have it
     : m_str(s), m_buf(s.utf8_str()), m_len(strlen(m_buf))
-#else
-    : m_str(s), m_buf(s.mb_str()), m_len(s.length())
-#endif
 {
-#if wxUSE_UNICODE
     wxASSERT_MSG(m_buf.data() != nullptr, wxT("Could not convert string to UTF8!"));
-#endif
     m_pos = 0;
 }
 
@@ -127,13 +121,10 @@ size_t wxStringInputStream::OnSysRead(void *buffer, size_t size)
 
 wxStringOutputStream::wxStringOutputStream(wxString *pString, wxMBConv& conv)
     : m_conv(conv)
-#if wxUSE_UNICODE
     , m_unconv(0)
-#endif // wxUSE_UNICODE
 {
     m_str = pString ? pString : &m_strInternal;
 
-#if wxUSE_UNICODE
     // We can avoid doing the conversion in the common case of using UTF-8
     // conversion in UTF-8 build, as it is exactly the same as the string
     // length anyhow in this case.
@@ -143,9 +134,6 @@ wxStringOutputStream::wxStringOutputStream(wxString *pString, wxMBConv& conv)
     else
 #endif // wxUSE_UNICODE_UTF8
         m_pos = m_conv.FromWChar(nullptr, 0, m_str->wc_str(), m_str->length());
-#else // !wxUSE_UNICODE
-    m_pos = m_str->length();
-#endif // wxUSE_UNICODE/!wxUSE_UNICODE
 }
 
 // ----------------------------------------------------------------------------
@@ -165,7 +153,6 @@ size_t wxStringOutputStream::OnSysWrite(const void *buffer, size_t size)
 {
     const char *p = static_cast<const char *>(buffer);
 
-#if wxUSE_UNICODE
     // the part of the string we have here may be incomplete, i.e. it can stop
     // in the middle of an UTF-8 character and so converting it would fail; if
     // this is the case, accumulate the part which we failed to convert until
@@ -207,10 +194,6 @@ size_t wxStringOutputStream::OnSysWrite(const void *buffer, size_t size)
         // not update m_pos as m_str hasn't changed
         return size;
     }
-#else // !wxUSE_UNICODE
-    // no recoding necessary
-    m_str->append(p, size);
-#endif // wxUSE_UNICODE/!wxUSE_UNICODE
 
     // update position
     m_pos += size;